The present invention relates to a fuze for an explosive projectile, particularly a submunition projectile (bomblet), with the fuze being of the type including an axially displaceable firing pin and a slide displaceable transversely to the longitudinal direction of the fuze housing and the projectile and provided with a detonation charge between a safety position, wherein the detonation charge is not aligned with the primary firing pin, and an armed position, wherein the detonation charge is aligned with the primary firing pin.
Bomblet projectiles are submunition projectiles, that is, secondary projectiles, which are transported in large numbers, e.g. sixty three bomblet projectiles arranged in seven rows, each containing nine bomblet projectiles, by a large-caliber carrier projectile over distances up to 30 km to above a target area and are there ejected at a height of, for example, 300 m. While the bomblet projectiles are dropping down or descending, they are mechanically set to detonate.
European published application No. EP-A 0,284,923, corresponding to U.S. Pat. No. 4,811,664 discloses a bomblet fuze provided with a safety device which includes a safety pin actuated by the action of centrifugal forces. To arrest the slide, the safety pin is configured to engage in a corresponding recess in the slide. The slide includes an ignition element or primer, which is ignited by a second firing pin, for a pyrotechnic delay path for self-destruction of the projectile if the primary firing pin did not cause the fuze detonator to act upon impact on the target. This may happen, for example, if such a secondary projectile (bomblet) ejected from a carrier projectile lands on soft ground, in a swamp, in snow, in tree branches, in high grass or in a camouflage net. The drawback of the prior art bomblet construction is the fact that, with the fuze in the armed position, the slide projects laterally far and unprotected from the fuze housing. This could very easily cause malfunctions, for example in rainy weather, in the initiation of the detonation charge or in the exposed ignition element of the delayed charge for the self-destruct function.
Another drawback is the arrangement of the second firing pin for igniting the detonator element at the outer unprotected end of the slide itself which projects far out from the side of the fuze housing. The second firing pin is provided with a heavy percussion or striking member and is rotatably fastened to the slide by means of a pin. If the fuze is armed by displacement of the slide out of the side of the fuze housing, centrifugal force from the inherent rotation of the bomblet should make the striking member effective and the solid firing pin should perform a movement of about 90.degree. on a small-radius partial circle and enter into the ignition element. The shape of the tip of the firing pin is solidly conical and flattened on one side, possibly in order to facilitate the penetration into the ignition element on a small circular arc. This fuze construction has the further great drawback that the slide which projects far from the fuze housing and its heavy firing pin-percussion member on the outside produces great eccentricities during rotation and thus destabilizing forces which act on the bomblet.
Moreover, if the projectile spins only slightly or there is insufficient centrifugal force, it may happen during the transverse displacement of the slide that the slide is displaced outwardly and the pivotal solid firing pin and the percussion member are released, but the striking energy for igniting the pyrotechnic delay composition is insufficient to self-destruct the projectile and the slide is not arrested in its outer armed position (see FIG. 6: Spring pin 24 at housing projection 25 of this reference). Another drawback for the free displaceability of the slide is that, for example, a spring biased pin (24) always exerts friction, that is a braking effect, between the slide and the housing. Moreover, once the spin is reduced and there is no longer any centrifugal force, a spring tensioned safety pin (27) also constantly presses against the side wall of the slide, and its friction and deceleration effect also acts against the displaceability of the slide.
If such a bomblet hits a soft target, the detonation charge may not be ignited by the first axially displaceable firing pin. Such a bomblet then lies around in the terrain as a dangerous dud and may be caused to explode at once by the first firing pin due to shock or impact, for example, if hit by a foot, or it may be activated for a delayed explosion by the second firing pin.